Class: ActionMailbox::Base

Inherits:
Object
  • Object
show all
Includes:
Callbacks, Routing, ActiveSupport::Rescuable
Defined in:
lib/action_mailbox/base.rb

Overview

Action Mailbox Base

The base class for all application mailboxes. Not intended to be inherited from directly. Inherit from ApplicationMailbox instead, as that’s where the app-specific routing is configured. This routing is specified in the following ways:

class ApplicationMailbox < ActionMailbox::Base
  # Any of the recipients of the mail (whether to, cc, bcc) are matched against the regexp.
  routing /^replies@/i => :replies

  # Any of the recipients of the mail (whether to, cc, bcc) needs to be an exact match for the string.
  routing "help@example.com" => :help

  # Any callable (proc, lambda, etc) object is passed the inbound_email record and is a match if true.
  routing ->(inbound_email) { inbound_email.mail.to.size > 2 } => :multiple_recipients

  # Any object responding to #match? is called with the inbound_email record as an argument. Match if true.
  routing CustomAddress.new => :custom

  # Any inbound_email that has not been already matched will be sent to the BackstopMailbox.
  routing :all => :backstop
end

Application mailboxes need to override the #process method, which is invoked by the framework after callbacks have been run. The callbacks available are: before_processing, after_processing, and around_processing. The primary use case is to ensure that certain preconditions to processing are fulfilled using before_processing callbacks.

If a precondition fails to be met, you can halt the processing using the #bounced! method, which will silently prevent any further processing, but not actually send out any bounce notice. You can also pair this behavior with the invocation of an Action Mailer class responsible for sending out an actual bounce email. This is done using the #bounce_with method, which takes the mail object returned by an Action Mailer method, like so:

class ForwardsMailbox < ApplicationMailbox
  before_processing :ensure_sender_is_a_user

  private
    def ensure_sender_is_a_user
      unless User.exist?(email_address: mail.from)
        bounce_with UserRequiredMailer.missing(inbound_email)
      end
    end
end

During the processing of the inbound email, the status will be tracked. Before processing begins, the email will normally have the pending status. Once processing begins, just before callbacks and the #process method is called, the status is changed to processing. If processing is allowed to complete, the status is changed to delivered. If a bounce is triggered, then bounced. If an unhandled exception is bubbled up, then failed.

Exceptions can be handled at the class level using the familiar ActiveSupport::Rescuable approach:

class ForwardsMailbox < ApplicationMailbox
  rescue_from(ApplicationSpecificVerificationError) { bounced! }
end

Constant Summary

Constants included from Callbacks

Callbacks::TERMINATOR

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(inbound_email) ⇒ Base

Returns a new instance of Base.



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# File 'lib/action_mailbox/base.rb', line 79

def initialize(inbound_email)
  @inbound_email = inbound_email
end

Instance Attribute Details

#inbound_email ⇒ Object (readonly)

Returns the value of attribute inbound_email.



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# File 'lib/action_mailbox/base.rb', line 70

def inbound_email
  @inbound_email
end

Class Method Details

.receive(inbound_email) ⇒ Object 



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# File 'lib/action_mailbox/base.rb', line 75

def self.receive(inbound_email)
  new(inbound_email).perform_processing
end

Instance Method Details

#bounce_now_with(message) ⇒ Object

Immediately sends the given message and changes the inbound email’s status to :bounced.



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# File 'lib/action_mailbox/base.rb', line 111

def bounce_now_with(message)
  inbound_email.bounced!
  message.deliver_now
end

#bounce_with(message) ⇒ Object

Enqueues the given message for delivery and changes the inbound email’s status to :bounced.



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# File 'lib/action_mailbox/base.rb', line 105

def bounce_with(message)
  inbound_email.bounced!
  message.deliver_later
end

#finished_processing? ⇒ Boolean

:nodoc:

Returns:

  • (Boolean) 


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# File 'lib/action_mailbox/base.rb', line 100

def finished_processing? # :nodoc:
  inbound_email.delivered? || inbound_email.bounced?
end

#perform_processing ⇒ Object

:nodoc:



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# File 'lib/action_mailbox/base.rb', line 83

def perform_processing # :nodoc:
  ActiveSupport::Notifications.instrument "process.action_mailbox", instrumentation_payload do
    track_status_of_inbound_email do
      run_callbacks :process do
        process
      end
    end
  rescue => exception
    # TODO: Include a reference to the inbound_email in the exception raised so error handling becomes easier
    rescue_with_handler(exception) || raise
  end
end

#process ⇒ Object 



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# File 'lib/action_mailbox/base.rb', line 96

def process
  # Override in subclasses
end